Objective: The aim of the present research was to investigate the mediating role of maladaptive core beliefs and eating disorder beliefs in the relationship between parental bonding and eating disorder symptoms. Method: The statistical sample of this study comprised second grade high school students (403 individuals) who were selected from among public girls’ schools in the city of Tehran, using multistep cluster sampling. All participants completed the Farsi versions of Parental Bonding Inventory PBI (Parker et al., 1979); Young Schema Questionnaire YSQ: Short Form (Young, 1998); Eating Disorder Belief Questionnaire EDBQ (Cooper et al., 1996), and Eating Disorder Inventory EDI (Garner et al, 1983). Validity and reliability of questionnaires were assessed using Cronbach’s alpha and factor analysis. The probable causal model was analyzed using covariance structure analysis or structure equation model.Results: Results showed that eating disorder beliefs and maladaptive core beliefs respectively play a moderating variable and a mediating variable in the relationship between parental bonding and eating disorder symptoms.Conclusion: Based on the mentioned evidence it could be concluded that parental bonding, primary maladaptive beliefs, and eating disorder beliefs can form bases for the development of eating disorder; however, each play different roles in the psychopathology of this disorder.